It started as a candlelight vigil for immigrant children who had been separated from their parents while crossing into the United States. A few dozen demonstrators gathered in front of the nondescript Immigration and Customs Enforcement facility in southwest Portland on June 17.

After the candles were blown out, some of the demonstrators decided to stay, stumbling onto a more effective form of protest with a simple line of reasoning: ICE cannot deport people if immigration judges, lawyers and litigants cannot physically enter its facilities.

A week later, the number of people outside the facility has ballooned, blockading the government building around the clock with their bodies, hastily scrawled poster board signs and a tandem bicycle. By Monday morning, a Federal Protective Services spokesman told The Washington Post, the only people inside the facility were government officials making sure the doors were securely locked.

Occupy Ice PDX was born. Buoyed by their success, organizers spread the word to like-minded people in other immigration hubs.

“We invite the rest of the country to join this movement, to gather and occupy your local ICE facility until it’s shut down,” one message said. “Bring candles, signs, noisemakers and tents. Most importantly, bring yourself. Even if you can only come down for a day, for an hour, your presence is important and needed. It takes ALL of us working together to stop this machine of terror.”

Demonstrators in other cities mobilized to duplicate the protest method.

In Detroit on Monday, an ICE spokesman said normal operations were “briefly disrupted” by protests, though essential functions eventually resumed. Photos showed demonstrators with signs, tents and folding chairs, sitting in the facility’s parking lot.

In New York, the ICE processing center on Varick Street canceled all hearings on Monday. Protesters blocked the loading dock ICE uses to transport immigrants into and out of the building, according to the Hill.

Sam Natale, 29, a protester and an attorney who lives in Manhattan, told the New York Daily News: “Part of the reason why we’re out here is to emphasize that the end of child separation is not the end of the problem.”

“We can claim a victory, if only for a day,” #OccupytICENYC said in a statement tweeted out Sunday. “201 Varick Street will not send anyone to abusive, inhumane immigration detention facilities tomorrow . . . We came, we stayed, we occupied, and for this brief moment, we have won.”

In Portland, demonstrators were entrenched at the start of their second week of protests. They had removed the American flag from the front of the building. In its place, they had put up a brown and yellow flag that says “Refugees Welcome.”

A planned rally at the center had grown so large it had to be moved to City Hall.

Rep. Steve King (R-Iowa), a staunch immigration opponent, compared the occupation with the attack on Harpers Ferry, the unsuccessful but significant pre-Civil War attack on a U.S. military arsenal that aggravated tensions between the North and the South.

On Monday, around 10:30 a.m., officers from the Federal Protective Service, which secures U.S. government buildings, went from tent to tent distributing notices for protesters to vacate federal property.

“While demonstrators have a lawful right to assemble and voice their concerns, blocking the building’s driveways or entrances is not permitted under federal law,” Billy J. Williams, U.S. attorney for the District of Oregon, said in a news release.

The fliers, which were also posted on the building, warned “individuals who continue to obstruct the entrance of this federal facility will be subject to arrest and prosecution in federal court.”

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